The present invention relates to a machine tool provided with a palette on which a workpiece is detachably mounted, and more particularly, to a cover unit for covering the machine tool to prevent cutting chips and machining liquid from being scattered externally.
In a conventional arrangement, a cover unit is disposed over the machine tool. The cover unit is provided with an opening portion having a predetermined opening region for facilitating maintenance of the machine tool. Further, a workpiece and a palatte are moved through the opening portion of the cover unit for undergoing machining to the workpiece in a machining region of the machine tool and for handling the workpiece outside the machining region.
In this instance, the opening area of the cover unit must be sufficiently large for facilitating inspection, handling and maintenance to the machine tool. However, the opening is much greater than outer profiles of the workpiece and the palette, and therefore, a large clearance may result when these items pass through the opening. Accordingly, there is a likelihood that cutting chips generated at the machining region and machining liquid applied to the workpiece may be splashed or scattered from the machining region to the outside through the large clearance.
Particularly, there has been proposed a machining tool providing two machining zones in the machining region, so that while one workpiece is subjected to machining at one machining zone, another workpiece is introduced into another machining zone through the opening. That is, the other workpiece is fixed to a palette at a non machining region outside the cover unit, and the other workpiece and the palette are introduced inside the cover unit through the opening during machining to the one workpiece at the one machining zone. With such arrangement, cutting chips and machining liquid attendant to the first machining zone may be scattered to a significant degree outside through the opening when the second workpiece is moved into the second machining zone through the opening.